The Dental Clinic

Room # 3 & 4, 2nd Floor, Taj Clinics, C-15/1 Block 3 Gulshan-e-Iqbal, Karachi, 75300

Root Canal Treatment Side Effects: What You Need to Know

A root canal treatment eliminates bacteria from an infected root canal to prevent reinfection and save the natural tooth. During a root canal procedure, the inflamed and infected pulp is removed, and the inside of the tooth is cleaned, disinfected, filled, and sealed. After the procedure is done, the dentist will send you home with instructions for pain management and how to care for the tooth while it recovers from treatment until the next follow-up. It is especially important to follow guidelines if a temporary filling or crown is in place. 

However, as the medication that is used to numb the mouth wears off, you may feel tenderness or mild soreness in the area for a few days. You may also experience some mild soreness in your jaw for keeping your mouth open during the procedure. Though these symptoms are temporary and respond well to over-the-counter medications. Your dentist may also prescribe you with stronger medications. In addition to the symptoms of soreness, some patients may also experience: 

  • Severe pain or pressure that lasts for more than a few days. 
  • Visible swelling inside and around the mouth. 
  • An allergic reaction to the medication, including hives, rash, and itching. 
  • Uneven bite 
  • Symptoms that you experienced prior to the treatment return. 

This article will highlight the common side effects of root canal treatments and tips for managing side effects of a root canal treatment. 

Common Side Effects of Root Canal Treatment and Tips for Management

While most people experience no complications after a root canal, there are some common side effects that you may experience. These side effects are usually mild and go away on their own within a few days.

Pain and restlessness 

One of the most common side effects of a root canal treatment is pain and restlessness. A root canal treatment involves removing the infected pulp using several tools. Therefore, the chance of surrounding tissue swelling increases. This is why most patients experience pain after a root canal procedure. However, the swelling normally subsides in 7 to 10 days. If the pain lasts longer than expected, reconsult your dentist because there are the chances that remnants of the pulp may still be in the root. 

Underfilling or overfilling 

Another major risk factor associated with root canal treatment is underfilling of the tooth. The tooth root is cleaned thoroughly by removing all the pulp to make enough space for a sealant filling. However, if the infectious pulp remains the gap is not filled properly, in addition to becoming infectious when the pulp interacts with the fillings. Thus, the pain becomes unbearable after a few months of root canal treatment because of the infectious pulp. 

In other cases, the tooth may be overfilled during the treatment. This leads to an inadequate bite and consistent pain. If you are facing traumatic pain after many months of the treatment, contact your dentist right away. 


During the root canal procedure, the tooth needs to be disinfected and the pulp needs to be removed from the canal chambers. The pulp of the tooth is in the canals in the center of the tooth and is filled with nerve endings. The pain could be a side effect of getting a root canal treatment done. 

Increased swelling 

Mechanical cleaning and the chemicals used during root canal treatment may irritate long-standing infections in dead teeth and cause them to flare-up. When this happens, it can lead to swelling in the area for a short period of time. 

Unequalled number of canals vs the roots

Another common side of root canal treatment that is often overlooked is the possibility of having an unequal number of canals than the roots. In this case a few of the canals won’t find any roots, causing them to disturb the surrounding teeth. The minor negligence can cause multiple future complications. Therefore, always consult a best dentist in Karachi, Pakistan to have a professional root canal treatment done.  

Improper sealings 

If your dentist fails to properly seal the tooth after a root canal treatment, the bacteria will penetrate the sealing and infect the tooth. This is why it is recommended to get a crown on the tooth after a root canal treatment. This reduces the risk of root canal treatment failure and severe pain. 


Developing an abscess after root canal treatment is another common side effect. An abscess is a pocket of pus because of a bacterial infection. To avoid a bacterial infection during root canal therapy, the infected pulp should be removed adequately without infecting the surrounding tissues. It is also important to ensure that the temporary filling is removed completely before a permanent filling, in addition to advising a crown to avoid a bacterial infection. 

Less common side effects of root canal 

When a root canal is unsuccessful the symptoms may return either a few months or a few years later. In some cases, retreatment is an option where the original root canal filling is cleans and the tooth is disinfected. The tooth is then refilled and resealed. The goal of treatment is to save the natural tooth as with any other root canal treatment. 

The success of a root canal treatment largely depends on eliminating the bacteria from the root canal system and then properly sealing it to prevent the bacteria from getting inside the tooth or roots. 

Nerve damage 

While nerve damage after a root canal treatment is rare, a common cause of extremely serious nerve damage is overfilling the tooth. As discussed earlier, overfills occur when excess material is packed in the canal. The excess material comes out of the tip of the root and can intrude the nerve below, causing serious damage. 

Another common cause of nerve damage is through the root canal instrument. Sometimes while cleaning the root canal, the dentist might extend the instrument past the tip of the root, puncturing the nerve canal. In more serious cases, the root canal file may break in the nerve canal. This can cause severe and intense pain, in addition to lifelong disability and complications. 

Long term effects of root canal treatment  

Tooth discoloration 

In a root canal treatment, the nerves are removed from the teeth which cause a slight discoloration in the tooth. However, this discoloration is not visible in most cases because a crown is usually required following a root canal treatment. Though in cases where a dental cap is not necessary, bleaching can be advised to remove the discoloration. 

Reduced tooth function 

After a root canal treatment, a tooth structure tends to become weaker. For this reason, the tooth does not function as previously, in addition to slightly increasing the risk of fracture. Therefore, it is recommended to get a dental crown fitted after a root canal treatment to avoid the risk of fracture. 

Risk of acute infection 

Infected and non-infected teeth that are treated with root canal treatment in some cases may become infected because of a root canal procedure. In this case, the treatment options include re-endo if the tooth is salvageable, otherwise extraction. 


Although rare, some patients may experience prolonged numbness, pain, or pressure after the procedure. Similarly, the local anesthesia fades after a few hours of treatment and you may experience mild discomfort within the first 24 to 48 hours. The discomfort can be managed with over-the-counter pain medication. However, speak to your dentist immediately if you are experiencing extreme pain around your teeth and gums. 

For highly qualified general dentists, such as Dr Saqib Minhas, a root canal treatment is a very common procedure. Meaning that they can eliminate any of the root canal risks with a skilled team and careful planning. Before the procedure, you can speak with your dentist about the potential complications that may occur during or after the treatment. 

Need a dentist in Gulshan-e-Iqbal area, Karachi? Schedule an appointment today! 

If you believe you need a retreatment, do not hesitate to contact a skilled dentist. 

At The Dental Clinic we understand the importance of prompt treatment. We have the best endodontists in our team who are certified to effectively provide treatment and relief. Patients worry that if the root canal they had years ago was unsuccessful, the same is likely to happen again. However, the endodontics has advanced significantly over the years. Your endodontist will examine whether you are a good candidate for retreatment and save your natural tooth. We are equipped with state-of-the-art amenities and dental technologies at the clinic. To get started, schedule an appointment, just contact us on 03312048149 or drop by at our clinic, Room # 3 & 4, 2nd Floor, Taj Clinics, C-15/1 Block 3 Gulshan-e-Iqbal, Karachi, 75300


What are the common side effects of root canal treatment? 

Common risks and complications of root canal treatment include mild and temporary pain because of inflammation in the tissues surrounding the tooth; darkening of the tooth; and tooth fracture because of reduced strength of the tooth. 

How long do root canal treatment side effects last?

Patients typically make full recovery after a root canal treatment within a few days to a week. 

What are the less common side effects of root canal treatment?

In a very small percentage of patients, the nerves around the tooth can be disrupted. This may cause numbness in the area. However, this usually goes away on its own in a few weeks. 

Can root canal treatment cause nerve damage?

Most root canal procedures are carried out without any issues but in some cases, you may experience nerve damage afterwards.

Is it normal to experience pain after root canal treatment?

You may experience mild to moderate pain after the root canal treatment. If the discomfort does not go away after a few days, you may require additional treatment. 

Can root canal treatment lead to tooth discoloration?

It is not uncommon for teeth to darken after root canal treatment. 

Can root canal treatment cause tooth fracture?

Root canal teeth are prone to fracture because of reduced strength of the tooth. 

What should I do if I experience side effects after root canal treatment?

Call your dentist or endodontist right away if you feel severe pain or pressure, swelling or if your bite feels uneven.